1. Technical Field
The present invention relates to a technique of displaying a line drawn on a display surface by a user.
2. Related Art
A touch-panel-type display device is used, which returns to a normal mode from a power saving mode in which less power is consumed than in the normal mode, in response to a touch by a user to the display device. For example, JP-A-2001-325071 discloses a controller with a touch sensor for operating equipment provided in a car, which gets out of a sleep mode in which little electricity is used, in response to a touch to the touch sensor.
When such a display device is used, if a user is unaware that the display device operates in a power saving mode, it is possible that the user will start drawing a line using a stylus pen, without waiting for the display device to return from a power saving mode to a normal mode. In this case, a line drawn after the display device enters a normal mode is displayed on a display surface of the display device; however, a line drawn while the display device is in the process of returning from a power saving mode to a normal mode is not displayed. This is because functions of the display device are not active during the process of returning from a power saving mode to a normal mode; accordingly, the display device does not recognize the line drawn during the process. In this case, a user has to again draw the line that was drawn while the display device was in the process of returning from a power saving mode to a normal. Such a situation may occur especially when a display device that uses cholesteric liquid crystal or electrophoresis is used. This is because such a display device has a memory ability to maintain a displayed image even after the display device enters a power saving mode; namely, an image is displayed in the same way in both a normal mode to a power saving mode; accordingly, it is difficult for a user to determine whether the display device is in a normal mode or a power saving mode.
The present invention has been made in view of the foregoing circumstances, and an aspect of the present invention provides a display device that recognizes a line drawn using an input device such as a stylus pen while the display device is in an operation mode in which positions of points of contact between the display device and the input device are not determined; recognizes a line drawn using the input device while the display device is in another operation mode in which positions of points of contact between the display device and the input device are determined; and displays the lines together.